Apparatus for severing composite glass



'mmw m J. PENMNG' APPARATUS FOR SEVERING COMPOSITE GLASS 2 SheetsSheet 1 Filed Dec. 15 192s INVENTOR APPARATUS FOR SEVERING' COMPOSITE GLASS File d Dec. 15, 1928 2 Sheets$heet 2' Patented July 29,1930

, UNITED STATES NICHOLAS J. PENNrNG, on PITTSBURGH, PENNSYLVANIA, assxerron T DUPLATE 003,-

PATENT QFFICE A PORATION, "A CORPORATION or DELAWARE nrrnnmrus'ron snvname comments eLass Application filed December 13, 1528. Serial No. 325,689.

This inventionrelates to apparatus for severing composite glass sheets by the application of heat preferably by the use of heat I glass-are cracked, and force is a j lied to'tear the plastic sheet,such tearing wil occur along whi ch-l1es to one side of. .the line of cracking of the glass and any the ine of heatingenerated by the passage of electric current through resistance elements. The heat as thus applied serves to crack the two glass 'so that all-defects incident to the operation lie on one side of the line of cut, in the strip of waste glass, which is cut Ofl. This is .ac-

c'omplished-by heating the plate'along a lineparallel to the proposed line of cut, but to one side thereof, sothat when the two sheets of stretching and' thi'n'ning of the plastic, incident to the tearing, will thus :.lie "in the waste strip. ,The'heat is preferably applied,

by means ofitwo sets of electrically heated ribbons, one' set of "which applies heat for a considerable period to heat the plate to one side of the lineof e1 1t,.so as to soften the plastic, while the other set applies heat only momentarily along the proposed line of cut to give the temperature necessary forcracking the glass sheets. One form of apparatus. for carrying out the process is. shown in the accompanying drawings, wherein Figure 1 is a longitudinal section through Fig. 2 is: a transverse section on the line lL-II ofFig.

the apparatus in position of use.

1. Fig. 3 is a wiring diagram. And Fig. 4

is an enlarged section through the sheet shows T ing how the separation takes place. j As indicated in Figs. 1 and 2, are; heat ing devices are preferably employed, one. on

top of thesheet to be out, and one below, but it will be understood that the process may be carried out with onlyone device, although not so rapidly. .The'two devices are duplicates, and each comprise a channel 'bar 1 of insulating material carrying a pair of resistance wires orribbons 2 and 3 extending over the-r0llers4,e of insulating material and sestretched or thinned, so that the joinder be cured to pairs of terminal blocks 5 and 6 carried by springs 7 and 8 for keeping the wires under tension. Current is supplied through '-the leads 9 and 10, the wires 2 and 3 being insulatedfro'm each other, sov that current may be supplied independently through each wire for different intervals of time, as later explained, this being controlled by the use of switches 11 and 12, as indicated diagrammatioallyin Fig. 3. r In-order to make a cut along the lines A, A,

the devices are applied, as indicated in Fig.

2, the plate to be out being made up of the usual glass sheets 13 andg ld cemented to the sheet of pyroxylin plastic 15, such as celluloid. The switches 11 are first closed so that a current passes through the wires 2, and this is continued until vthe lastic lying between the channels 1, 1 is soflie be readily stretched and pulled apart or torn after the glass sheets 13 and 14 are cracked. The switches 12 are now closed, so that current passes through the wires 3 which contact withthe'wfglass so that they heatv it very rapidly. This flow is required only for a second or two, when the channels are removed and a wetted tool is touched to the lines just heated by the wires 3. The glass sheets 13 and 114 immediately crack along the lines A, A,

and'assoon as, this -occ11"rs,'the'operator grasps the two parts of theplate, and pulls them apart, as indicated in Fig. 4. This can bened, so that it may done, because the plastichas been sufliciently softene'd ,fromfthegaction, of the wires 2.

Furthermore, this separation of the plastic occurs along a lineto the left of the lines A, A, since the softening of the plastic is for the most part on such side, and adjacent the wire 2. In ractice, the separation'occurs as indicated in Fig. 4',-th'e tongue B of plastic be ing pulled out from between-the glass sheets. This tongue-is'subsequently removed with a knife.

scribed, involving the softening of the plastie to one side of the proposed lines of out A,

The method: of; separation, as just detween the plastic and the glass sheets at this point isnot impaired. Where such jointis impaired to the slightest extent or the slightest separation occurs, the product may be ruined, as a separation or let go after once 1 starting, keeps progressing inward untilthe appearance of the'sheet is spoiled and replace-f is to be separated through its center so that j both edges must be perfect, the sheet is cut ment is required. The procedure described avoids this difliculty, as all the defects incident to the separation lie in the sheet of waste glass to the left of the lines A, A. If a; sheet asabove described, and then theprocess is plishing this function.

applied tocut, off the defective edge to. the width of about one inch; The proce'ssdoes not necessarily require that the cracking along the lines A A', should beaccomplished by means of the heated wires 3, 3, although this is the preferred procedure. If desired, such cracking may be 'accomplished'by'the use of a diamond or a scoring wheel. Other means, aside from the wires 2, 2, might also be used to heat the plate to theleft of the lines of out A, A and soften the plastic, although 4 the resistance wires are preferred for accom- What I claim is:

1. Apparatus for severing a composite glass plate by electricity, asupporting bar having a channel in one side, and a pair of resistance I conductors mounted in said channel extendinglongitudinally thereof in parallel, one of glass plate by electricity, a supporting bar inward from the first conductor.

said conductors beinglocated along the side of the channel and the other one being spaced g i q 2. Apparatus for:- 'severlng a composite having a channel in one side, and a pair of resistance conductors mounted in said channel extending longitudinally thereof in parallel, one ofsaid conductors lying in the channel to the rear of the "plane of the front edges of "the channel, so that*-such conductor is spaced away from the surface'of the sheet to be severed, while the other conductor islecated at the plane of said edges so that it contacts with said surface.

In testimony whereof, I have hereunto subscribed myname this 11th day of December i .IL'rENmNGl 

